Lamellorthoceratidae Teichert, 1961

Cichowolski, Marcela & Rustán, Juan José, 2020, Lamellorthoceratid cephalopods in the cold waters of southwestern Gondwana: Evidences from the Lower Devonian of Argentina, Acta Palaeontologica Polonica 65 (2), pp. 305-312 : 307

Family Lamellorthoceratidae Teichert, 1961

Remarks.—The controversy surrounding this family concerns not only the higher taxonomic rank including it, but also the generic level. While some researchers considered the Lamellorthoceratidae as more or less monogeneric (e.g., Babin 1966; Bandel and Stanley 1989; Niko 1991; Kröger 2008), others proposed several genera to be included in it (e.g., Sweet 1964; Stanley and Teichert 1976; Zhuravleva and Doguzhaeva 2004). The Lamellorthoceratidae was first established in order to unite the genera Arthrophyllum Beyrich, 1850 , and Lamellorthoceras Termier and Termier, 1950 . Additional genera were described subsequently: Gorgonoceras Zhuravleva, 1961 , from the Middle Devonian of the Central Urals, Coralloceras Balashov and Zhuravleva, 1962 , from the Lower and Middle Devonian of Algeria, Esopoceras Stanley and Teichert, 1976 , from the Lower Devonian of USA, Plicatoceras Niko, 1991 , from the Lower Devonian of Japan, Nucleoceras Kolebaba, 1999 , from the Ludlow of the Czech Republic, and Syndikoceras Zhuravleva and Doguzhaeva, 2004, from the Lower Devonian of the Russian Arctic and the Middle Devonian of North Africa. The validity of these genera has been disputed (e.g., Sweet 1964; Babin 1966; Bandel and Stanley 1989; Niko 1991; Zhuravleva and Doguzhaeva 2004). While Zhuravleva and Doguzhaeva (2004) proposed five lamellorthoceratid genera ( Arthrophyllum , Lamellorthoceras , Esopoceras , Coralloceras , and Syndikoceras), based on the ultrastructure of shell wall and internal parts, apical angle, septal necks, ornamentation, etc., others considered these traits as having a low taxonomic value, being rather variable intraspecifically, and through ontogeny (e.g., Bandel and Stanley 1989). With the exception of newly proposed taxa, Zhuravleva and Doguzhaeva (2004) did not provide diagnosis of each genus. It is therefore difficult make comparisons between these genera in terms of Zhuravleva’s and Doguzhaeva’s (2004) work.